Need LAN longer than 100m

I run a Christian camp in Florida and I'm trying to network our buildings together. My big problem is that I'd like to connect a network in two buildings that are about 600 feet from each other. I could even deal with the signal being at 10 mb/sec if I had to, but I just want it to be reliable. I don't want to mess with wireless. Any ideas? You guys have been so helpful in the past.

The proper thing to do would be to lay some fiber optics and buy two ethernet media converters. Expensive, but fast, reliable and future-proof.

If possible, you could put any powered ethernet device between the two segments. A simple hub halfway between the buildings would do. You need to power and house the thing though.. Needs very good cables for high speed.

Yes, there are special "long range" bridges/modems, but these are rather slow and expensive too. What if one of the boxes dies and the company that made them has gone bankrupt?

Maybe you can get a fast internet connection in both locations? In that case, you could set up a VPN tunnel and use the ISP-s backbone.